Underreamer for well drilling apparatus



Oct. 4, 1932. R. SIMMONS 1,830,216

UNDERREAMEH FOR WELL DRILLING APPARATUS Filed June 8.' 1928 v 2Sheets-Sheet l INVENTOR 1 ATTORNEY,

Oct. 4, 1932. R. P. SIMMONS UNDERREAMER FOR WELL DRILLING APPARATUS 2Sheets-Sheet 2 Filed June 8. 1928 Fla 42p J? JAE/ am Patented Oct. 4,1932 RICHARD I. SIMMONS, OF NEW YORK, N. Y.

UNDERREAMER FOR WELIi DRILLING APPARATUS Application filed June 8, 1928.Serial No. 283,848.

This invention relates to improvements in under reamers for welldrilling apparatus.

The primary object of the invention residesin a rotary drill forenlarging the dlameterin a preformed well holev to facilitate thelowering of a follower casing therelnto, and means by which the drillmay be lifted from the well without disturbing the position of thefollower casing.

Another object is the provision of an under reamer for attachment tothecore barrel of well drilling apparatus embodying rotary drill bitseXpansible beyond the plane of the side walls of the core barrelto cut aplane for a follower casing, and retractable withm the plane of the corebarrel to allow the free withdrawal of the under reamer through thefollower casing, the expansion and retraction of the drill bits beingremotely controlled by an operator at the surface of the well.

A further objectis to provide an under reamer including rotary bitsjournalled 1n sliding carriages which are simultaneously controlled by asliding actuating member which controls the expansion and retraction ofthe same. i t lVith these and other objects in view, the inventionresides in certain novel construction and a combinatio'n and arrangementof parts, the essential. features of which are hereinafter fullydescribed, are particularly pointed out in the appended claims, and areillustrated in the accompanying drawings, in which Figure 1 is afragmentary side elevation of the lower end of a well drilling apparatusprovided with my improved under reamer. Figure 2 is an enlarged verticallongitudinal sectional View therethrough on the line 22 of Figure 1.,

Figure 3 is a horizontal sectional View on the line 33 of Figure 2.

Figure 4 is a detail perspective view of the cam actuating member.

Figure 5 is a detail perspective View of one of the sliding carriages. V

Figure 6 is a vertical longitudinal sectional view through. a slightlymodified form.

Figure 7 is a horizontal sectional view on the line 7-7 of Figure 6.

Referring to the drawings by reference characters, the numeral 10designates my improved under reamer in its entirety which includes acylindrical body 11 threaded at opposite ends as at 12 and13. Thethreaded end 12'is shown screwed to the lower end of a rotary debrisbarrel 14 which receives the residue cut by the under reameiywhile thethreaded end 13 screws to a depending housing 15 to which the lowerdrill head of the drilling apparatus is attached.

The body 11 is provided with a transverse rectangular shape recess 16which extends entirely therethrough, while the top and bottom walls ofthe recess are provided with axially aligned square openings 17for'slidably receiving a cam actuating member 18. The top and bottom ofthe cam member are provided withears 19 for the attachment of a part bywhich sliding movementmay be imparted to the camv member. This slidingmovement may be imparted either from below or above and in the drawingsI have shown a slidable rod 20 passing downward throughthe core barrelfromthe surface of a well, and which is pivotally connected to the upperear 1 9 as at 21. The opposite sides of the member 18 are provided withcam slots 22 which include parallel branch slots 23 which merge intosingle slots 24. The lower end of the cam slots 22 are closed byremovable blocks 25, as it will be appreciated that to form the peculiarshaped slots, it is necessary to cut into the member from one endthereof.

Slidable horizontally within the recess 16 are carriages 26,respectively disposedon opposite sides of the cam actuating member andwhich have their inner sides-recessed as at 27 to accommodate the memberand allow lateral sliding movements to be imparted'to' the carriagesWithout striking the member or each other. The opposed side walls of therecesses 27 have opposed pairs of inwardly extending lugs orcam'followers 28 which enter the cam slots 22 in opposite sides of thecommodating rotary drill bits or reamers 30 which are mounted onvertical shafts 31 ournalled in the carriages. The exterior surfaces ofthe drill bits are provided with vertical teeth 32 by which the walls ofa preformed well hole are cut to enlarge the diameter thereof.

The upper portion of the body 11 is provided with upwardly inclinedpassages 33 which open into the debris barrel 14 to allow the materialcut by the drill bits to pass into the dbris barrel where itaccumulates, and when full, the apparatus is lifted to the surface ofthe well and the debris barrel emptied.

In practice, assume that a well hole of a particular diameter is beingdrilled by a primary drill at the lower end of the apparatus and whichis of a size to freely allow the cylindrical body 11 to gradually movedownward as the drilling progresses. However, it is desirable to pass afollower casing 34 down into the well while the apparatus is inoperation but to accommodate the follower casing it becomes necessary toincrease the diameter of the well hole, which is accomplished by myimproved under reamer 10. After the under reamer has been lowered intothe well with the'bits in retracted position, the cam actuating member18 is moved downwardly by a push upon the rod 20, whereupon the lugs 28move from the common slot 24 to the spaced branch slots 23 as shown inFigure 2 of the drawings- This causes the carriages 26 to move outwardin opposite directions, which extendsthe cutting sides of'the bitsbeyond the peripheral wall of the body 11 for cutting a planetherebeyond of a size to accommodate the followercasing. As hereinbeforestated, the material cut by the rotary bits upon rotation of the body 11is received in the core barrel 14, which when filled, is

Y lifted to the surface and emptied. Before raising the core barrel andthe under reamer which is connected thereto, without disturbing thefollower casing, it becomes necessary to retract the rotary bits withinthe cylindrical body 11 which is. accomplished by pulling upward on therod 20. This upward movement causes the lugs 28 to be guided into thecommon slots 24 which draws the carriages' inwardly to the positionshown in dotted lines in Figure 3 of the drawings, whereupon the cuttingsurfaces of the drill bits are inward of the plane of the peripheralwall of the cylindrical body so as not to. strike the follower casingduring the upward movement of the under reamer through the followercasing. It will therefore be seen that the drill bits may be expanded orretracted from the surface of the well and at such times during adrilling of, a well as may become necessary. 7 V

The device enables an operator to progressively cut the wall of thewell, so as to provide a clearance for operating the well equiplargementof the diameter of well bore is 7 limited by the relatively smallpropelling curve of the cam. The waste produced by the cuttingaction ofthe'reamer tools against the wall of the well bore is conducted throughthe space between the radially spaced reamer tools upward through thewaste openings 33 to the core barrel 14. The reamer tools are mounted incarriages which support the tools so that they constantly clear theirown mounting,while the carriages have close sliding fit with the head orbody 11, and the waste cannot fill the clearance spaces between theworking parts, so as to block the operationof the tool, nor can thewaste accumulate at the base of the tool or' the head of the casing, sothat the progressive vented, 7 v p l. a In Figures 6 and-7 of thedrawings, I have shown a slightly modified form of my invention whereinthe expansion and retraction of lowering of the casing is prevthe rotarybits is automatically controlled by the direction of rotation of thepart in which they are-mounted. In this form the cylindrical rotatablebody is designated at 35 having eccentric arcuate shaped. slots 36therein and similarly shaped recesses 37. Disposed for slidingmovementin the recesses 37 are rotary drill bits 38 having shafts 39slidable in the cam slots 36.- Upon clockwise rotation of thecylindrical body 35, the drill bits will automatically move to anextended position by-reason of the cutting surface of the sameprojecting slightly beyond the plane of the side of the bodywhichfrictionally engages the wall of the preformed hole and by reasonof the centrifugal force imparted thereto.

However, when it is desired to move the drill bitsto a retractedposition, the rotation of the cylindrical body is reversed which causesthe drill bits to move inwardly to the position shown in dotted lines inFigure 7 of the drawings. When in a retracted position, the drill bitsare held from accidental movement by spring catches 4O mounted'in one ofthe side walls of the slots 36 and which engage the shafts 39 to placea' slight tension thereon. The purpose of this form of apparatusis thesame as that of the preferred form, namely to cut a plane beyond thesides of the cylindrical body. to facilitate the lowering of a followercasing into a well to protect the walls of the same against accidentalcave-in.

In the usual practice of drilling wells, end drillsdetach the materialin advance. of the drilling unit or below it andlthis Waste is carriedinto a core barrel. The wall of the well thus formed is then enlarged bya reaming tool. The dependant housing 15 in the present assemblyrepresents the core barrel which is located b8l0W' the reaming unit, andthe superimposed housing 34 carrying the barrel 14, represents a dbrisbarrel for receiving the waste or dbris produced by the action of thereaming tools against the wall of the well.

While I have described what I deem to be the most desirable embodimentof my invention, it is obvious that many of the details may be variedWithout in any way departing I from the spirit of my invention, and Itherefore do not limit myself to the exact details of constructionherein set forth nor to anything less than the whole of my inventionlimited only by the appended claims.

What is claimed as new is 1. An underreamer having a body provided withcam slots, each of said slots having a a portion disposed more inwardlyof the outer face of the body than another portion of said slot, and areaming tool having a shaft mounted in one of said slots with the bodyof the tool shiftable outwardly of the face of the body and inwardly ofthe face of the body.

:2. An underreamer having a body provided with a transverse slot, areamer slidable against the body in said slot and adapted to bepropelled from a contracted inward position to an expanding outwardposition when said body is rotated, to cause said reamer tool to shiftby frictional engagementwith the wall of the well.

In testimony whereof I have afixed my signature. 7

RICHARD P. SIMMONS.

